Removable Closing Device for Containers, Particularly Liquid Food Product Containers, Comprising a Tamprering Indicator

ABSTRACT

A removable closing device ( 1 ) for a liquid food product container ( 2 ), having a neck ( 3 ) fixable in fluidtight manner to the container, and a removable cap ( 4 ) for closing the neck in fluidtight manner; the cap and the neck have mating, inclined-surface coupling means, in particular, screw means; the cap is cup-shaped, and includes a sleeve portion ( 5 ) having a threaded portion ( 6 ) and an end collar ( 7 ) which faces the neck in use; the sleeve portion having, between the threaded portion and the collar: weakening means ( 21 ) permitting, in use, elastic radial deformation of the threaded portion, so that the cap, at least the first time it is inserted, can be clicked onto the neck; and a tampering indicator ( 10 ) having shear-off stop means ( 11 ) which, in use, upon attempted removal of the cap from the neck, cooperate with and are sheared by mating stop means ( 12 ) on the neck ( 3 ).

The present invention relates to a removable closing device for containers, in particular liquid food product containers, comprising a tampering indicator. More specifically, the invention relates to a screw cap/threaded neck type device which is easy to produce and assemble, and wherein the tampering indicator is easy to produce and compact.

As is known, with food containers, it is important that the user be given a clear indication of whether or not the container has been opened, while at the same time allowing the user to open and close the container as required, and employment of maximum automation by the manufacturer of the product (the packaged liquid food product).

At present, these conflicting requirements are met using either conventional containers, comprising closing devices in the form of foldable or adhesive tabs, or using closing devices made of plastic material and substantially comprising pull-off or screw caps.

In the first case, repeatedly opening/closing the container is awkward for the user, and fluidtight sealing is not always good, thus resulting in potential leakage of the liquid food product, and in alteration of the taste of the product, caused by air or pollutants, e.g. bacteria, entering the container.

In the second case, pull-off caps do not always safeguard against leakage of the liquid food product, and are not always resealable in fluidtight manner; while screw caps are either combined with a shear-off, e.g. pull-off or pierceable, seal, which increases production cost, or are provided with a blocking ring device which is sheared when the container is opened for the first time. In the latter case, however, the caps must be screwed or forced by deformation onto the necks, thus increasing assembly cost. Moreover, the devices described are relatively bulky.

It is an object of the present invention to eliminate the drawbacks of the above known closing devices, by providing a removable closing device for containers, particularly liquid food product containers, which is fast and easy to use; is fast, easy and cheap to assemble; is cheap to produce; is compact and highly reliable; is capable of withstanding repeated opening/closing, while still ensuring excellent fluidtight sealing and so safeguarding against contamination or leakage of the liquid food product; and can be clicked on, while still effectively indicating unsealing of the container.

According to the present invention, there is provided a removable closing device for a container, in particular a liquid food product container, as claimed in Claim 1.

More specifically, the closing device according to the invention comprises a cap and a neck connectable to each other by means of respective threaded coupling portions. The cap is cup-shaped, and comprises: a sleeve portion, in turn comprising a said coupling portion and an end collar facing the neck in use; and a tampering indicator. Between said coupling portion and the collar, weakening means are provided to weaken the sleeve portion and permit, in use, elastic radial deformation of at least said coupling portion such that the cap, at least for its first insertion onto the neck, can be clicked onto the neck.

According to one aspect of the invention, the tampering indicator comprises shear-off stop means which, in use and upon attempted removal of the cap from the neck, cooperate with and are sheared by mating stop means on the neck.

More specifically, the weakening means comprise at least two circumferential slits formed through part of the axial extension of the end collar; and the shear-off stop means comprise one or two flexible tabs formed in one piece with the end collar and projecting inside one or both said slits; each tab having a stop tooth on its free end.

The neck comprises a first end portion with fastening means for attachment to the container; and a second end portion facing the cap in use. Between said first and second end portion, at least one annular projection is provided, of such a radial height as to interfere radially with the tooth of each said tab.

Consequently, when assembling the closing device according to the invention onto the container, the container can be fitted with the cap and the neck connected to each other in a preseal position, i.e. with the threaded portion of the cap partly force-fitted onto the corresponding threaded portion of the neck; and the cap can subsequently be set to a fully-sealed, perfectly fluidtight position by simply pressing the cap axially to force-fit it onto the neck (which can be done easily using automatic assembly means).

That is, by virtue of the radial slits, the coupling portion of the cap is flexible radially outwards, so that the cap can first be assembled in the preseal position, and then forced to click into the fully-sealed position.

Moreover, when the cap is in the fully-sealed position on the neck, the tooth of each tab is located beyond the annular projection, which, alongside any relative movement of the cap into the unsealing position, therefore constitutes axial stop means mating with the tabs.

That is, whereas, when clicking the cap onto the neck, the tabs flex radially outwards to get past the annular projection (particularly if the respective teeth have lead-ins), when unsealing the cap—whether this is done by unscrewing or axially removing the cap off the neck—the tabs flex radially inwards and “jam” against the annular projection until their ultimate break load is reached. At which point, the tabs are sheared to allow removal of the cap, while at the same time indicating tampering (i.e. that the container has been unsealed due to a first opening thereof after packaging).

A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:

FIG. 1 shows a side view of a container closing device in accordance with the invention and fitted to a known bag container shown only partly in section for the sake of simplicity;

FIG. 2 shows a section, along line II-II, of the FIG. 1 closing device in a fully-sealed operating position;

FIG. 3 shows a section, at roughly 120° with respect to line II-II, of the FIG. 1 device in a second preseal or preassembly operating position.

With reference to FIGS. 1 to 3, number 1 indicates as a whole a removable closing device for a container 2 (FIG. 1), in particular a liquid food product container. Container 2, e.g. a “bag” type container, is widely known in the industry and therefore not described for the sake of simplicity.

Device 1 comprises a neck 3 fixable in known and fluidtight manner to container 2; and a removable cap 4 fixable removably and in fluidtight manner to neck 3. In the example shown, cap 4 and neck 3 have mating, inclined-surface coupling means enabling removal, by simultaneous rotation and translation, of cap 4 off neck 3.

In the non-limiting embodiment shown, the mating, inclined-surface coupling means comprise, for example, screw/nut screw means described in detail below, but which may obviously be replaced by other inclined-surface coupling means, such as bayonet coupling means.

More specifically, cap 4 is cup-shaped, and comprises: a sleeve portion 5, in turn comprising a coupling portion 6 and an end collar 7 facing neck 3 in use; and a tampering indicator indicated as a whole by 10 (FIG. 1).

According to a first aspect of the invention, weakening means 21 are provided between coupling portion 6 and end collar 7 to weaken sleeve portion 5 of cap 4 and to permit, in use, elastic radial deformation of at least coupling portion 6, so that cap 4, at least the first time it is inserted onto the neck, can be clicked onto neck 3.

According to a second aspect of the invention, tampering indicator 10 comprises shear-off stop means 11 which, in use and upon attempted removal of cap 4 from neck 3, cooperate with and are sheared by mating stop means 12 on neck 3.

In the preferred embodiment, coupling portion 6 of sleeve portion 5 of cap 4 is an internally threaded nut screw portion. In combination, neck 3 comprises a first end portion 31 with fastening means 38 (e.g. a flange) for attachment to container 2; and a second end portion 32 (FIGS. 2 and 3) opposite 31 and facing cap 4 in use, and which is defined by a hollow, externally threaded, tubular screw portion bounded by a substantially smooth inner lateral wall 33.

At least one annular projection is located between end portions 31 and 32, and in use constitutes said stop means 12, as described in detail below.

According to the invention, said weakening means comprise at least two circumferential slits 21 formed through sleeve portion 5 of cap 4, for a predetermined angular and axial extent between coupling portion 6 and collar 7. Circumferential slits 21 are diametrically symmetrical, and have preferably the same angular extent, e.g. may be four in number, spaced 90° apart.

According to the invention, shear-off stop means 11 comprise at least one elastically deformable tab 22 formed in one piece with end collar 7 and projecting inside a respective circumferential slit 21 a having a greater axial extent than the other slits 21, as described in detail below; and a tooth 23 formed on a free end of tab 22.

In the preferred embodiment shown, shear-off stop means 11 comprise two tabs 22, each having a tooth 23 on its free end, and each projecting inside a respective circumferential slit 21 a diametrically opposite the other.

Tooth 23 of each tab 22 projects radially from tab 22 towards neck 3, and annular projection 12 formed on neck 3 is of such a radial height as to interfere radially, in use, with tooth 23 of each tab 22.

More specifically, circumferential slits 21 a, inside which tabs 22 project, are formed along the axial extension of collar 7 only, and along a longer portion of it than the other slits 21, so that, when cap 4 is in a fully-sealed position (FIG. 2) on neck 3, tooth 23 of each tab 22 is located past annular projection 12 (i.e. on the side facing flange 38), which therefore constitutes said mating axial stop means when cap 4 is moved into an unsealing position or even only a partial unsealing position (FIG. 3).

Tooth 23 of each tab 22 has a lead-in, so that, when cap 4 is moved with respect to neck 3 into said fully-sealed position in FIG. 2, tooth 23 forces respective tab 22 to flex radially outwards. Conversely, facing cap 4, teeth 23 have perpendicular stop surfaces 40 (FIG. 2), so that, when the cap is moved into the partial unsealing position in FIG. 3, i.e. to remove cap 4 from neck 3, teeth 23 come to rest axially against annular projection 12, thus arresting the movement of the cap into the unsealing position, until the respective tabs break, which preferably occurs at weakened root portions 45 of the tabs (shown by the dash lines in FIG. 1).

This is achieved by the shape of teeth 23, as the cap is moved into the unsealing position, causing tabs 22 to flex radially inwards and so jam beneath projection 12.

Cap 4 comprises a top wall 50, from which a cylindrical projection 51 and a tubular sleeve 52 (FIGS. 2 and 3) project sequentially inside and coaxially with sleeve portion 5. Cylindrical projection 51 is larger in diameter than the inside diameter of tubular screw portion 32 of neck 3, so that an edge 53 of cylindrical projection 51 defines an axial stop to arrest cap 4 on neck 3; and tubular sleeve 52 has an outside diameter smaller than the diameter of cylindrical projection 51, so as to mate in fluidtight manner with inner lateral wall 33 of tubular screw portion 32 of neck 3.

Preferably, tubular sleeve 52 of cap 4 or inner lateral wall 33 of tubular screw portion 32 of neck 3 (or both) has static sliding sealing means, e.g. projections 55, and/or one or more O-rings 56 (shown by the dash line in FIG. 2) are provided between tubular sleeve 52 and inner lateral wall 33. 

1) A removable closing device for a container, in particular a liquid food product container, comprising a neck fixable in fluidtight manner to the container, and a removable cap fixable removably and in fluidtight manner to the neck; said cap and said neck having mating, inclined-surface coupling means enabling removal, by- simultaneous rotation and translation, of the cap off the neck; said cap being cup-shaped and comprising: a sleeve portion, in turn comprising a coupling portion and an end collar facing said neck in use; and a tampering indicator; characterized in that weakening means are provided between said coupling portion and the end collar to weaken said sleeve portion and permit, in use, elastic radial deformation of at least said coupling portion so that the cap, at least the first time it is inserted onto the neck, can be clicked onto the neck; said tampering indicator comprising shear-off stop means which, in use, upon attempted removal of the cap from the neck, cooperate with and are sheared by mating stop means on the neck. 2) A device as claimed in claim 1, characterized in that said mating, inclined-surface coupling means comprise screw means. 3) A device as claimed in claim 2, characterized in that said coupling portion of the sleeve portion of the cap is an internally threaded nut screw portion. 4) A device as claimed in claim 1, characterized in that said weakening means comprise at least two circumferential slits formed through said sleeve portion of the cap, for a predetermined angular and axial extent between said coupling portion and said end collar. 5) A device as claimed in claim 4, characterized in that said circumferential slits are diametrically symmetrical, and have the same angular extent. 6) A device as claimed in claim 4, characterized in that said shear-off stop means comprise at least one elastically deformable tab formed in one piece with said collar and projecting inside a said circumferential slit; and a tooth formed on a free end of said tab. 7) A device as claimed in claim 6, characterized in that said shear-off stop means comprise two tabs, each having a tooth on its free end, and each projecting inside a respective said circumferential slit diametrically opposite the other. 8) A device as claimed in claim 6, characterized in that said neck comprises a first end portion having fastening means for attachment to said container, and a second end portion opposite the first and facing said cap in use; at least one annular projection being located between said first and said second end portion. 9) A device as claimed in claim 8, characterized in that said tooth of each said tab projects radially from the tab towards said neck; and in that said annular projection is of such a radial height as to interfere radially with the tooth of each said tab; said circumferential slits, inside which said tabs project, being formed along the axial extension of said collar, to such an axial length that, when said cap is in a fully-sealed position on the neck, the tooth of each tab is located past said annular projection, which therefore constitutes said mating axial stop means when the cap is moved into an unsealing position. 10) A device as claimed in claim 9, characterized in that said tooth of each tab is so shaped that, as the cap moves with respect to the neck into said fully-sealed position, the tooth forces the respective tab to flex radially outwards; whereas, as the cap moves into said unsealing position, the tooth comes to rest axially against said annular projection, thus arresting the movement of the cap into said unsealing position, until said tab breaks. 11) A device as claimed in claim 8, characterized in that said second end portion is defined by a hollow, externally threaded, tubular screw portion bounded by a substantially smooth inner lateral wall. 12) A device as claimed in claim 11, characterized in that said cap comprises a top wall, from which a cylindrical projection and a tubular sleeve project sequentially inside and coaxially with said sleeve portion; the cylindrical projection being larger in diameter than the inside diameter of said tubular screw portion of the neck, so that an edge of the cylindrical projection defines an axial stop to arrest the cap; and said tubular sleeve having an outside diameter smaller than the diameter of said cylindrical projection, so as to mate in fluidtight manner with said inner lateral wall of the tubular screw portion of the neck. 13) A device as claimed in claim 12, characterized in that said tubular sleeve of the cap or said inner lateral wall of the tubular screw portion of the neck has static sliding sealing means. 